According to commit [12d6f21e: x86: do not PSE onCONFIG_DEBUG_PAGEALLOC=y], the intention of debug_pagealloc_enabledwas to force additional testing of splitting large pages due tocpa. Presumably this was because when bootmem was retired, all thepages would be mapped forcing the protection to be applied laterwhile the system was running and races would be more interesting.

This patch is trading additional CPA testing for better detectingof memory corruption with DEBUG_PAGEALLOC. I see no issue with thisper-se, but I'm cc'ing Ingo for comment as it was his patch and thisis something that should go by the x86 maintainers.